linux-kernel - Re: [PATCH] security/keys/trusted: Allow operation without hardware TPM

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 19 Mar 2019 18:56:29 -0400
From:   Mimi Zohar <zohar@...ux.ibm.com>
To:     Dan Williams <dan.j.williams@...el.com>,
        James Bottomley <jejb@...ux.ibm.com>
Cc:     Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>,
        "linux-nvdimm@...ts.01.org" <linux-nvdimm@...ts.01.org>,
        Roberto Sassu <roberto.sassu@...wei.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        David Howells <dhowells@...hat.com>, keyrings@...r.kernel.org
Subject: Re: [PATCH] security/keys/trusted: Allow operation without hardware
 TPM

Hi Dan,

On Mon, 2019-03-18 at 17:30 -0700, Dan Williams wrote:

Sorry for the late reply.

> On Mon, Mar 18, 2019 at 5:24 PM James Bottomley <jejb@...ux.ibm.com> wrote:
> >
> > On Mon, 2019-03-18 at 16:45 -0700, Dan Williams wrote:
> > > Rather than fail initialization of the trusted.ko module, arrange for
> > > the module to load, but rely on trusted_instantiate() to fail
> > > trusted-key operations.
> >
> > What actual problem is this fixing?  To me it would seem like an
> > enhancement to make the trusted module fail at load time if there's no
> > TPM rather than waiting until first use to find out it can never work.
> > Is there some piece of user code that depends on the successful
> > insertion of trusted.ko?
> 
> The module dependency chain relies on it. If that can be broken that
> would also be an acceptable fix.
> 
> I found this through the following dependency chain: libnvdimm.ko ->
> encrypted_keys.ko -> trusted.ko.
> 
> "key_type_trusted" is the symbol that encrypted_keys needs regardless
> of whether the tpm is present.

Commit 982e617a313b ("encrypted-keys: remove trusted-keys dependency")
removed the dependency on trusted keys.  masterkey_trusted.c should
only be included if "CONFIG_TRUSTED_KEYS" is enabled.  Is
CONFIG_TRUSTED_KEYS enabled?

Mimi